标题：Historical and future anthropogenic warming effects on droughts, fires and fire emissions of CO2 and PM2.5 in equatorial Asia when 2015-like El Niño events occur
摘要：In 2015, El Niño contributed to severe droughts in equatorialAsia (EA). The severe droughts enhanced fire activity in the dry season(June–November), leading to massive fire emissions of CO2 and aerosols.Based on large event attribution ensembles of the MIROC5 atmospheric globalclimate model, we suggest that historical anthropogenic warming increasedthe chances of meteorological droughts exceeding the 2015 observations inthe EA area. We also investigate changes in drought in future climatesimulations, in which prescribed sea surface temperature data have the samespatial patterns as the 2015 El Niño with long-term warming trends.Large probability increases of stronger droughts than the 2015 event areprojected when events like the 2015 El Niño occur in the 1.5 and 2.0 ∘C warmed climate ensembles according to the ParisAgreement goals. Further drying is projected in the 3.0 ∘Censemble according to the current mitigation policies of nations. We use observation-based empirical functions to estimate burned area, fireCO2 emissions and fine (<2.5 µm) particulate matter(PM2.5) emissions from these simulations of precipitation. There are nosignificant increases in the chances of burned area and CO2 andPM2.5 emissions exceeding the 2015 observations due to pastanthropogenic climate change. In contrast, even if the 1.5 and2.0 ∘C goals are achieved, there are significant increases in theburned area and CO2 and PM2.5 emissions. If global warming reaches3.0 ∘C, as is expected from the current mitigation policies ofnations, the chances of burned areas and CO2 and PM2.5 emissionsexceeding the 2015 observed values become approximately 100 %, at least inthe single model ensembles. We also compare changes in fire CO2 emissions due to climate changeand the land-use CO2 emission scenarios of five shared socioeconomicpathways, where the effects of climate change on fire are not considered.There are two main implications. First, in a national policy context, futureEA climate policy will need to consider these climate change effectsregarding both mitigation and adaptation aspects. Second is the considerationof fire increases changing global CO2 emissions and mitigationstrategies, which suggests that future climate change mitigation studiesshould consider these factors.
